Life Cycle Assessment Results Research Articles

A rapid review of meta-analyses and systematic reviews of environmental footprints of food commodities and diets

Systematic reviews, sometimes including meta-analyses, are often presented as an approach for identifying healthy and sustainable diets. Here we explore to which extent systematic review protocols have been adopted by studies comparing environmental impacts of foods based on Life Cycle Assessment (LCA) results, and to which extent they comply with the PRISMA protocol for transparent reporting. Out of 224 studies screened, seven explicitly define themselves as systematic reviews, and/or claim to carry out meta-analyses. Of these, only one acknowledges a review protocol, while none complies with all the PRISMA criteria. Neither do we believe that reviews of LCA results can comply with all the criteria or carry out meta-analyses, due to underreporting on standard deviations and artificial sample sizes in LCAs. Nonetheless, reviews of food commodities and diets based on LCA results would benefit from better aligning with criteria in systematic review protocols.

An integrated life cycle and water footprint assessment of nonfood crops based bioenergy production

Biomass gasification, especially distribution to power generation, is considered as a promising way to tackle global energy and environmental challenges. However, previous researches on integrated analysis of the greenhouse gases (GHG) abatement potentials associated with biomass electrification are sparse and few have taken the freshwater utilization into account within a coherent framework, though both energy and water scarcity are lying in the central concerns in China’s environmental policy. This study employs a Life cycle assessment (LCA) model to analyse the actual performance combined with water footprint (WF) assessment methods. The inextricable trade-offs between three representative energy-producing technologies are explored based on three categories of non-food crops (maize, sorghum and hybrid pennisetum) cultivated in marginal arable land. WF results demonstrate that the Hybrid pennisetum system has the largest impact on the water resources whereas the other two technology options exhibit the characteristics of environmental sustainability. The large variances in contribution ratio between the four sub-processes in terms of total impacts are reflected by the LCA results. The Anaerobic Digestion process is found to be the main contributor whereas the Digestate management process is shown to be able to effectively mitigate the negative environmental impacts with an absolute share. Sensitivity analysis is implemented to detect the impacts of loss ratios variation, as silage mass and methane, on final results. The methane loss has the largest influence on the Hybrid pennisetum system, followed by the Maize system. Above all, the Sorghum system demonstrates the best performance amongst the considered assessment categories. Our study builds a pilot reference for further driving large-scale project of bioenergy production and conversion. The synergy of combined WF-LCA method allows us to conduct a comprehensive assessment and to provide insights into environmental and resource management.

Comparison between conventional solvothermal and aqueous solution-based production of UiO-66-NH2: Life cycle assessment, techno-economic assessment, and implications for CO2 capture and storage

Metal-organic frameworks (MOFs) are a new class of materials that has shown great potential in catalysis, sensing, separations, and carbon capture and storage. Conventionally, MOFs are synthesized at lab-scale using organic solvent-based systems, leading to high environmental burdens and high operating costs, which ultimately hinders the large-scale production and application of MOFs. Aqueous synthesis of MOFs overcomes such difficulty by eliminating the organic solvent, which makes it an environmental-friendlier and economically-favorable alternative to the current production method. However, further quantitative analysis is required to compare the environmental and economic performances of the two methods. Here, we used life cycle assessment (LCA) coupled with techno-economic analysis (TEA) to evaluate the environmental and economic performances of different UiO-66-NH2 production methods. When the solvothermal method was replaced by the aqueous solution-based method, the LCA and TEA results suggest the environmental burdens and cost of UiO-66-NH2 production were reduced by up to 91% and 84%, respectively. By using aqueous solution-based method, the cradle to gate carbon footprint, and production cost of UiO-66-NH2 were estimated to be 43 kg CO2 eq/kg, and $15.8/kg, respectively. We further applied our LCA results to reassess the role of UiO-66-NH2 in carbon capture and storage (CCS) and compare its environmental performance with current benchmark (amine-based solvent). Our results show that electricity produced from UiO-66-NH2 CCS system could potentially have better environmental performance (lower Global Warming Potential (GWP)) than that of the amine-based CCS system if the sorbent loss is less than 0.0017 tonne/tonne CO2 captured. This work is the first comprehensive LCA-TEA study that quantifies the substantial environmental and economic benefits of using the aqueous solution-based systems to produce UiO-66-NH2, and the analysis in this work is intended to be a starting point for further systematic studies on the full life-cycle impacts of MOFs.

Comparative analysis on environmental and economic performance of agricultural cooperatives and smallholder farmers: The case of grape production in Hebei, China.

Agricultural modernization and intensification have been regarded as a significant way to support agricultural development and improve farm income in China. Agricultural cooperatives have played an important role in promoting the modernization and intensification of Chinese agricultural sector. Given the increasing concerns about environmental harm, however, it still remains unclear whether and the extent to which agricultural cooperatives contributes to reducing environmental impacts of agricultural production. Hence, this study performed an environmental evaluation using life cycle assessment for three different organization forms of grape production in Changli County, Hebei Province, China: smallholder farmers, farmer-owned cooperatives and investor-owned firm-led cooperatives. Then the results of life cycle assessment were monetarized and cost benefit analysis was used to evaluate the economic performance of these three organization forms of grape production. The results demonstrate that investor-owned firm-led cooperatives present an overall improvement in environmental and economic performance with the lowest weighted environmental index (integrating all impact categories into a single score), the highest net profit and the highest total net benefit. The results also show a difference in potential improvement in environmental impacts and economic returns between cooperatives and smallholder farmers. Additionally, the production and application of organic and chemical fertilizer and pesticide have been identified as major contributors to total environmental damage.

Combining Life Cycle Assessment and Circularity Assessment to Analyze Environmental Impacts of the Medical Remanufacturing of Electrophysiology Catheters

Sustaining value after the end-of-life to improve products’ circularity and sustainability has attracted an increasing number of industrial actors, policymakers, and researchers. Medical products are considered to have great remanufacturing potential because they are often designated as single-use products and consist of various complex materials that cannot be reused and are not significant in municipal recycling infrastructure. The remanufacturing of electrophysiology catheters is a well-established process guaranteeing equivalent quality compared to virgin-produced catheters. In order to measure if using a remanufactured product is environmentally beneficial compared to using a virgin product, life cycle assessment (LCA) is often used. However, focusing on one life cycle to inform on the environmental-beneficial use fails to guide policymakers from a system perspective. This study analyzes the environmental consequences of electrophysiology catheters considering two modeling perspectives, the implementation of LCA, including a cut-off approach and combining LCA and a circularity indicator measuring multiple life cycles. Investigating the LCA results of using a remanufactured as an alternative to a newly-manufactured catheter shows that the global warming impact is reduced by 50.4% and the abiotic resource use by 28.8%. The findings from the system perspective suggest that the environmental savings increase with increasing collection rates of catheters.

Life cycle assessment of electricity generation from sugarcane bagasse hydrochar produced by microwave assisted hydrothermal carbonization

Microwave assisted hydrothermal carbonization (MAHTC) is a promising strategy for fuel production from sugarcane bagasse. Even though microwave heating has been reported to facilitate product (hydrochar) yield, energy properties and heating efficiency during hydrothermal carbonization (HTC) process, the environmental consequences of MAHTC treatment were still not clear. This study evaluated the environmental impact associated with 1 MJ electricity generation from sugarcane bagasse hydrochar through life cycle assessment (LCA) method, focusing on the critical role of process-based parameters to provide insights for optimization of MAHTC treatment. Specifically, two different allocation factors (energy content and economic value) and five environmental impact categories (climate change, freshwater eutrophication, freshwater ecotoxicity, human toxicity and fossil depletion) were assessed in this study. The LCA results revealed significant contribution of MAHTC process on climate change and fossil depletion because of large energy consumption used to maintain the system at designed temperature. Discharge of liquid phase from MAHTC process resulted in severe eutrophication impact especially when economic value was used as allocation factor. Gas emission from hydrochar combustion caused most toxicity related impacts indicating essential requirement of further investigation to quantify different gaseous composition. Based on LCA results, sensitivity analysis indicated hydrochar yield and carbon content as the top two influential factors on total environmental consequences. Comparison study with other fuel sources were further conducted to identify the influence of substituted energy sources. The overall results suggested MAHTC as promising method for bagasse utilization and energy retention efficiency as important indicator for optimization of MAHTC treatment or the sake of high-quality products and good environmental performance.

Environmental Impacts of Glass- and Carbon-Fiber-Reinforced Polymer Bar-Reinforced Seawater and Sea Sand Concrete Beams Used in Marine Environments: An LCA Case Study.

Application of glass- or carbon-fiber-reinforced polymer (GFRP/CFRP) bars makes the direct use of seawater and sea sand concrete (SWSSC) in construction feasible, which is of high interest in order to conserve the limited resources of fresh water and river sand. The present paper performed the life cycle assessment (LCA) of constructing three kinds of beams (GFRP/CFRP bar-reinforced SWSSC beams, and steel bar-reinforced common concrete (SRC) beam) in marine environments to show the environmental benefits of using FRP bar-reinforced SWSSC beams in marine environments. According to ISO 14040 and ISO 14044, stages including production, transportation, construction, use and end-of-life are within the LCA’s boundary. The ReCiPe method and eight main environmental impact categories were used to characterize the environmental impacts of those beams. LCA results indicate that one cubic meter SWSSC possesses much lower environmental impacts in terms of all eight categories compared with common concrete with the same volume when used in marine environments, with reduction rates from 26.3% to 48.6%. When the two transportation distances were set as 50 and 20 km and without considering the difference in service life, compared to SRC beam, GFRP-SWSSC beam performs better in six categories and CFRP-SWSSC beam performs better in four categories. When considering increased transportation distance and the higher durability performance, the advantageous categories for GFRP-SWSSC and CFRP-SWSSC beams increase to seven and six, respectively. The environmental impacts of all the three beams are mainly affected by the production stages.

Life Cycle Assessment of a Point-Absorber Wave Energy Array

Wave energy has a large global resource and thus a great potential to contribute to low-carbon energy systems. This study quantifies the environmental impacts of a 10MW array of 28 point-absorber wave energy converters, by means of a process-based life cycle assessment (LCA). Midpoint and Cumulative Energy Demand LCA results are presented over 19 impact categories, representing impacts encompassing human health, ecosystems and resource availability. Three scenarios are undertaken to represent the use phase of the array, identified as a particularly uncertain input, with very little long-term operation of wave energy arrays available to validate assumptions. The resultant global warming potential of the array ranges from 25.1- 46.0 gCO2e/kWh over a 95% confidence interval, 23-43 times lower than conventional fossil fuel electricity generation. The Energy Payback Time of the array ranges between 2.6-5.2 years. LCA results are found to be particularly sensitive to annual energy production across all impact categories, and to assumptions associated with the frequency of marine operations over a number of categories quantifying the production of greenhouse gases. This LCA has been undertaken at an early stage in the WEC product development and will inform innovative research focused on further reducing the environmental impacts of electricity generation.

Life Cycle Assessment of Biofuels.

Life cycle assessment (LCA) assesses the environmental burdens or impacts of products from cradle to grave. It is also possible to assess such burdens or impacts for parts of the life cycle. A brief overview is given of LCA methodology. A number of choices have to be made in the goal and scope definition, inventory analysis, and impact assessment stages of life cycle assessments. Such choices can have substantial impacts on LCA outcomes. There are uncertainties in outcomes linked to inventory data and modeling. In the case that future biofuels and production processes are studied, assessment outcomes are characterized by relatively large uncertainties. Choices and uncertainties should be considered in the interpretation stage of life cycle assessments. Methodologies applied to several important environmentally relevant aspects of biofuel life cycles are discussed. These aspects are: emissions of substances impacting climate, depletion of virtually nonrenewable abiotic resources, primary energy demand, and water footprint. LCA can be useful in identifying life cycle stages and processes that are major contributors to environmental burdens, for determining the energetic return on energy invested in biofuels, for the identification of environmental trade-offs, and for comparing the life cycle environmental burdens of products.

Comprehensive assessment of CO2 methanation: which H2 production pathway is practicable for green methane production in terms of technical, economic, and environmental aspects?

The analytic hierarchy process was performed to determine the best alternative for green methane production based on the results of technical assessment, economic analysis, and life cycle assessment.

Integrated LCA and OPEN LCA-CML baseline analysis on environmental impact associated with the plastic packaging waste management system of Rubavu city Rwanda

Over the past few decades, the life cycle assessment (LCA) has been established as a critical tool for evaluating environmental issues of chemical processes and material cycles. Plastic bottles are the most used materials for packaging beverages and other liquids. In Rubavu, wasted plastic bottles end their lives in Rutagara. This is an open dumpsite that is home to all of the different types of generated waste of Rubavu city, and its management is alarming. This study analyses the impact on the environment associated with the existing plastic bottle waste pathways in Rubavu, Rwanda, from the cradle to the grave perspective until the other process in Nairobi Kenya, as an extended process. Questionnaires, Interviews, Literature: scientific papers, government reports and internet websites were used through this study to get both primary and secondary data. Open LCA CML (baseline) method was applied to analyze the environmental impacts caused by plastic bottles during their management, focusing on its parameters conspicuously: acidification potential, climate change (GWP100), depletion of abiotic resources (elements, ultimate reserves), depletion of abiotic resources (fossil fuels), eutrophication (generic), freshwater aquatic ecotoxicity( FAETP inf), human toxicity (HTP inf), marine aquatic ecotoxicity (MAETP inf), ozone layer depletion (ODP steady-state), photochemical oxidation (high NOx), terrestrial ecotoxicity (TETP inf). Two alternatives to these were also analysed: sanitary landfill, and recycling, described as scenarios 1 and 2. In this framework, the result of LCA shows that the use of landfill was found to have the highest adverse environmental effects, and this process has resulted in high global warming potential due to plastic bottle packaging waste decomposition effects as they release methane and ethylene, which contributes significantly to the greenhouse gases.

A Comprehensive Life Cycle Assessment Study of Innovative Bifacial Photovoltaic Applied on Building

Bifacial photovoltaic (BPV) module is a new type of photovoltaic module, which can simultaneously utilize solar radiation from the front and the back side to produce more power generation. In this article, this BPV module was innovatively applied on building, and a demonstration building was designed and set up. The building includes the diversification of forms and reflection utilization. The BPV module improved power generation performance by 10.7% ~ 12.7% compared with the mono-facial module. Combined with experimental test, simulation and enterprise investigation, a multi-index life cycle assessment (LCA) method for BPV modules is established, and include economic, energy and environmental indicators. The application potential of different forms of BPV modules is analyzed and compared with mono-facial module. The energy payback time (EPBT) and greenhouse gas payback time (GPBT) of BPV solar house were 6.6 and 2.3 years, while the EPBT and GPBT of BPV inclined roof were 5.0 and 1.7 years. Economic analysis shows that BPV applied on building can compensate for all the input cost and even have more additional benefits. Compared with mono-facial module, BPV modules have higher benefits in all aspects. According to the LCA results, the optimization suggestions for the BPV demonstration building are given.

Environmental assessment of an Indian municipal wastewater treatment plant in Rajasthan

ABSTRACT Wastewater treatment plant (WWTP) reduces environmental load by improving the quality of effluent sewage water. A wastewater treatment plant during its operation, consumes energy for circulation and aeration of water, utilise chemicals such as anti-foaming agents, coagulants and flocculants and release gaseous emissions and solid waste (sludge). It is necessary to consider the environmental impacts of all these activities realistically. Life cycle assessment (LCA) is used to calculate the potential environmental impact associated with the operation of WWTP. In this study, LCA was carried out for a WWTP located in Jaipur in the state of Rajasthan, India. CML 2001 method was used for the life cycle impact assessment using GaBi 8.0 software. The objective of this study is to quantify the environmental impact associated with the operation of a WWTP and to identify the environmental hotspots among different processes within the WWTP. The LCA result of the WWTP reveals that the sequencing batch reactor process 1 and 2 have the highest environmental impacts within the WWTP as this process consumes the highest amount of electricity whereas the pretreatment process has the least environmental impact.

Integration of Sustainability Criteria and Life Cycle Sustainability Assessment Method into Construction Material Selection in Developing Countries: The Case of Vietnam

A sustainable development concerning economic, environmental, and social aspects is a global need as well as challenge in general and especially regarding the selection of construction materials. However, it is assumed that the importance of sustainability criteria is different in developed and developing countries. This is relevant for the application of Life Cycle Sustainability Assessment, a method that integrates the established methods for economic, ecological, and social evaluation (Life Cycle Costing, Life Cycle Assessment, and Social Life Cycle Assessment) without explicitly including importance weightings. This paper aims to review the reality of sustainable development in construction material selection in Vietnam, a developing country. A list of 18 sustainability criteria was set up by reviewing previous studies and using a questionnaire. These criteria were ranked and used to calculate the importance of weightings based on the Analytic Hierarchy Process method and a Likert scale. The results showed that the “price of material” was ranked as the first among the sustainability criteria. It is also pointed out that 42.06, 29.96, and 27.98 are the weightings of Life Cycle Costing, Life Cycle Assessment, and Social Life Cycle Assessment results, respectively. Besides, 11 obstacles for integrating sustainability criteria into material selection were identified in the questionnaire, and 4 out of them were marked as showing “high” importance.

Real time Energy Efficiency Operational Indicator: Simulation research from the perspective of life cycle assessment

CO2 emissions during ship building, maintenance, and scrapping are not be involved when defining Energy Efficiency Operational Indicator (EEOI). However, these CO2 emissions can only show its value during operation phase of ship life. In order to evaluate the effect of CO2 emissions during ship building, maintenance, and scrapping on energy efficiency, a real time EEOI definition was put forward, a life cycle assessment (LCA) calculation framework was established, and a ship propulsion model with main diesel engine was built. A bulker carrier YUMING was taken as the case ship. CO2 emissions during ship building, maintenance, and scrapping were calculated. Main engine revolution and real time EEOI value with other parameters were obtained by simulating in different ship draft. The results show that life cycle assessment result will explicitly increase the real time EEOI value especially in lower engine speed and lower ship draft. The engine revolution at the lowest EEOI value will increase explicitly by life cycle assessment result. It means that the lower limit of ship speed should increase during slow steaming. Therefore, slow steaming may bring less environmental benefit if the life cycle assessment result is involved.

The Role of Cycle Life on the Environmental Impact of Li6.4La3Zr1.4Ta0.6O12 based Solid‐State Batteries

AbstractThis study compares the environmental impacts of a lithium‐ion battery (LiB), utilizing a lithium iron phosphate cathode, with a solid‐state battery (SSB) based on a Li6.4La3Zr1.4Ta0.6O12 garnet‐structured electrolyte. It uses a hybrid life cycle assessment (LCA), according to two functional units, delivery of 50 MJ of electrical energy and kg of battery, to expand the system boundary. The results of the process LCA indicate that the environmental impact of LiBs is lower than SSBs across most environmental impact categories. Conversely, the input–output upstream global warming potential (GWP) of the LiBs, calculated by hybrid LCA, is higher than that of the SSBs. Sensitivity analysis shows that the SSB cycle life must increase from 100 to 2800 to achieve a GWP impact lower than that of LiBs and therefore outperform LiBs in this environmental impact category. The study, therefore, demonstrates that research into SSBs must be accelerated to achieve a functional and safe battery technology with a reduced impact on the environment.

Indirect GHG emissions in hydropower plants: a review focused on the uncertainty factors in LCA studies

Although Life Cycle Assessment (LCA) is standardized, there is a wide range of approaches and discussions of the methodology evaluating of environmental impacts in different contexts in energy production. This review aims to present some findings, and highlight and discuss factors that influence the Life cycle Assessments (LCAs) of Hydropower Plants (HPPs) such as: indirect emissions; different stages of HPPs (construction, operation and decommissioning), the scale/productivity of HPPs; types of projects (reservoir and run-of-river), and land use. This study presents the comparison of different energy sources through the LCA and the comparison between several HPP with their different characteristics. Most of the results obtained by HPP LCAs indicate that the construction phase is the most influential phase for indirect emissions due to the use of steel and concrete. There is an important relationship between impact and production, since plants with higher productivity will have their impacts diluted during their lifetime. The comparison of the LCA results of HPPs with the LCA of other energy sources indicates that, for the category analyzed (Global Warming Potential- GWP), HPPs have a good environmental performance considering the emissions quantified. The object of this study is indirect emissions and not direct emissions, which are important, but require another approach. This review also indicates some uncertainties related to the LCA of the HPPs and the need to conduct future studies on the environmental impacts of UHEs. We also present suggestions that should contribute to improve the use of the LCA methodology.

Environmental and Economic Assessments and Uncertainties of Multiple Lignocellulosic Biomass Utilization for Bioenergy Products: Case Studies

Life-cycle assessment (LCA) and techno-economic analysis (TEA) were applied to assess the economic feasibility and environmental benefits of utilizing multiple biomass feedstocks for bioenergy products under three different technological pathways with consideration of uncertainties. Three cases were studied for the production of pellets, biomass-based electricity, and pyrolysis bio-oil. A Monte Carlo simulation was used to examine the uncertainties of fossil energy consumption, bioenergy conversion efficiency, stochastic production rate, etc. The cradle-to-gate LCA results showed that pellet production had the lowest greenhouse gas (GHG) emissions, water and fossil fuels consumption (8.29 kg CO2 eq (equivalent), 0.46 kg, and 105.42 MJ, respectively). The conversion process presented a greater environmental impact for all three bioenergy products. When producing 46,929 Mg of pellets, 223,380 MWh of electricity, and 78,000 barrels of pyrolysis oil, the net present values (NPV) indicated that only pellet and electricity production were profitable with NPVs of $1.20 million for pellets, and $5.59 million for biopower. Uncertainty analysis indicated that pellet production showed the highest uncertainty in GHG emission, and bio-oil production had the least uncertainty in GHG emission but had risks producing greater-than-normal amounts of GHG. Biopower production had the highest probability to be a profitable investment with 85.23%.

Distance-to-target weighting in LCA\u2014A matter of perspective

PurposeWeighting can enable valuable support for decision-makers when interpreting life cycle assessment (LCA) results. Distance-to-target (DtT) weighting is based on the distance of policy (desired) targets to current environmental situations, and recent methodological DtT developments are based on a weighting perspective of a single region or country, considering mainly environmental situations in consuming countries or regions. However, as product supply chains are spread over many countries, this study aims at developing additional weighting approaches (producer regions and worst-case regions) and applying them in a theoretical case study on a global scale.MethodsThe current study is carried out to understand the influence of and the effect on weighting results of different countries and regions with their specific environmental policy targets. Based on the existing Ecological Scarcity Method (ESM), eco-factors for the three environmental issues climate change, acidification, and water resources were derived for as many countries as possible. The regional eco-factors were applied in a case study for steel and aluminum considering the three different weighting approaches on different regional scales.Results and discussionThe analysis revealed significant differences in the obtained weighting results as well as strengths and limitations in the applicability of the examined perspectives. Acidification was showed to be highly important with between 80 and 92% of the aggregated weighting results among the perspectives where water-scarce countries were not involved. Water-scarce countries had a significant influence (75–95%) when they were part of the examined case study.ConclusionsThe developed approaches enable the assessment of global value chains in different producer regions as well as the utilization of the conservative worst-case-regions approach. The approaches can foster future decision-making in LCA contexts while providing country-specific results based on different weighting perspectives in national, regional, and global contexts. However, for a complete implementation of the presented approaches, further data gathering is needed on environmental situations and policy targets in different countries as well as regionalized life cycle data.

A Review on the Applicability of Life Cycle Assessment to Evaluate the Technical and Environmental Properties of Waste Electrical and Electronic Equipment

Acrylonitrile–butadiene–styrene (ABS) copolymer and high-impact polystyrene (HIPS) are the plastics most commonly found in waste electrical and electronic equipment (WEEE), although properties generally decline with recycling. Technical studies are important in assessing the properties of recycled plastics and obtaining better evidence of their return or not to the same production cycle, through a study of their impacts and life cycle assessment (LCA). This article aimed at a literature search for information that demonstrates the importance of considering the technical property results of LCA studies on WEEE plastics. LCA studies show that recycling WEEE plastics, when compared with virgin raw material, prevents 87% of ABS gas emissions, in addition to reducing energy consumption by up to 90% for ABS and HIPS. However, some technical properties of recycled WEEE polymer material, such as impact strength and ultimate elongation, decline when compared to virgin materials, which may hinder their reinsertion into the same production cycle. These properties can be enhanced by preparing compatible mixtures of ABS and HIPS, or by mixing them with virgin polymers. Recycled ABS (not mixed with another material) can return to the same production cycle when the goal is to preserve the modulus of elasticity. Studies that investigate properties using LCA are scarce. However, they are important in determining the viability of the material returning or not to the same production cycle, which would impact the process and produce different LCA results. Recycled ABS and HIPS polymers from WEEE can return to the same function even if some properties decline, since properties can be improved when the polymers are properly mixed or made compatible, thereby lowering costs and primarily minimizing the negative environmental impacts.